Right Gents had loads of soft faults so tested voltage and it was showing 13.7 at battery on tick over 2000 revs same under load drops to 12 so deduced that alternator gone it was the original and I have done 145k so not a bad deduction - so changed it but I am still getting the same results anyone have any ideas what it could be ?

Could be a number of things, do the obvious and check battery leads are ok. i would check all electrical connections are good (unplug/reconnect), check all screw connections are tight, clean with electrical contact cleaner all spade connectors. Have a look at relays where possible, perhaps a winding is breaking down.

If you have a portable radio turn it on and place it near the running engine, if there are any shorts it will create a lot of interference (any arcing transmits a wide band radio signal and also can cause a lot of current resistance).

If your really unlucky it could be the replacement alternator. In the "good old days" you could do your own referb' :- diode pack, new brushes and nose bearing.

Sorry cant be of more help, i guess you will have to break out the multi-meter and start doing point to point checks for continuity.

Yes think so it was so much easier in the old days as you say doing own refurb was really satisfying

If you have a set of jump leads try using one to connect the engine block to the battery -ve terminal and see if it improves things. Any lump of metal or bolt head on the engine block will do.

Will do I had something similar with my old p38 the lead from the alt to the battery was corroded internally
This all started when I had all the tensioners and pulleys replaced all belts were under good tension very odd